class MyHashSet(object):

    def __init__(self):
        self.stack = [0] * (10 ** 6 + 1)

    def add(self, key):
        """
        :type key: int
        :rtype: None
        """
        self.stack[key] = 1

    def remove(self, key):
        """
        :type key: int
        :rtype: None
        """
        self.stack[key] = 0

    def contains(self, key):
        """
        :type key: int
        :rtype: bool
        """
        if self.stack[key]:
            return True
        else:
            return False
